Hello! I (tried, at least) converted an old laptop to a Debian home server, and I was trying to set up duckdns.org and to enable port forwarding on my router. internet connection was working, I installed packages, docker, immich, etc, and then suddenly (I don’t know exactly when) it refuses to connect to the internet. It does connect to local addresses (I can ssh into it) but ping google.com and any other internet-involving command fail. I had set up a rule on the router to forward port 80 to the device’s port 80, but I then removed the rule and it still does not connect to the internet. I rebooted the router but nothing changed. Any idea what could be? the router is a Vodafone router.

I changed the hostname to debianserver but on the router it is still written debian. Also, it’s the only device with unknown ipv6

thanks in advance!

EDIT: I rebooted again the server, and now ipv6 is not unknown anymore, and the hostname is correct. however, it still does not connect to the internet

EDIT 2:

only one device (debianserver) has this problem, other devices work as before

EDIT 3:

I don’t know if it’s useful or not, but if I boot a live debian USB in the server internet works

SOLUTION: aaaaand no it does not work, after restarting docker it seems to work because all the brodges are yet to be created and it takes some time, after like 30 seconds it does not work as before :(

  • edit the file /lib/systemd/system/docker.service
  • append the flag --bip=192.168.3.1/24 to ExecStart=....
  • systemctl daemon-reload
  • systemctl restart docker

docker was the fucker that messed everything up and made me lose a few hours!

EDIT 4:

it seems that ip route flush 0/0 restores the internet connectivity until reboot… I don’t know what does this means but can be a temporary workaround I guess? I really have no idea how to solve this

FINAL EDIT: I gave up. I removed debian and installed fedora, and now it all works like a charm

  • Stantana
    2•11 months ago

    Something is completely shutting your server off from the internet, despite it having full LAN access. The only time I’ve run into this exact issue was when I misconfigured the firewall on a server, effectively only allowing for local connections. I simply started over by reinstalling Debian, wiping all my mistakes. But it could also be a setting on your router, and without you knowing what changes you made it’s hard to give any reasonable advice.

    These are just shots in the dark, and other might offer better solutions but I’d try;

    1. Boot the laptop into a live session directly from USB. All settings are default. Test again, either wget or maybe ping a website. If it works, it’s the server setup and I’d start over. If not…

    2. Try reversing all changes on the router, give the server a different static IP.

    3. Back up the router configuration to a file, consider making notes of important changes, reset the router and try again. If it STILL doesn’t work you can restore the important settings. If it works, you can reimplement the settings from your notes. (unless we’re talking manually imported VPN certificates and similar lol)

    Sorry I wasn’t able to help you out, I’m hosting from home and it’s a fantastic thing when things

    I don’t know if it’s useful or not, but if I boot a live debian USB in the server internet works

    Haha yes, as mentioned. The issue is a setting on your laptop server installation. The simplest thing is just reinstalling and starting over.

    • tubbaduOP
      2•11 months ago

      The issue is a setting on your laptop server installation. The simplest thing is just reinstalling and starting over.

      this is probably a good news I think, because it’s only tedious but easy to solve If there’s a way to do it without having to reinstall immich on docker would be awesome, but perhaps it’s faster to reinstall everything than to look for a way to do this

      thank you very very very VERY much for your help!!!

      • Stantana
        1•11 months ago

        Happy to help, sorry I can’t offer a simpler solution that avoids reformatting. It’s probably doable if you want to do more fine grain troubleshooting but I’ve never found it to be worth the time.

        For my home self-hosting I also prefer pre-made scripts exactly to avoid having to manually set up everything. It’s such a slog and particularly if I have to restart from scratch. What’s the goal of your project, perhaps something like Yunohost or even DietPi could save you a lot of work and get straight to the fun of self-hosting?

        • tubbaduOP
          2•11 months ago

          What’s the goal of your project?

          I have my brother’s old laptop with the screen broken, so I thought to convert it to a server for my huge pictures library I have on my external ssd installing immich, it’s been a while since I’m reading things about this and now I finally have the chance to do it! I finished reinstalling now and internet works fine. I’ll run a ping linux.org after every single step so if this happens again I’ll at least know who’s the guilty!

          thanks again for your time and help!